Question

What fallacy is it when an argument attacks the person rather than the person's beliefs?

Answer 1

That kind of fallacy is called Argumentum ad Hominem.  It means the argument is addressed to the person; attacking that person instead the issue. There is an irrelevance because the argument is against to the person making a claim, rather against to the claim itself. An example is judging a person's social status or attitude, like calling his strategies aren't effective to finish a certain task because of his untidiness and laziness.